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The Curious Incident of the Dog in the Night-Time | Study Guide

Mark Haddon

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The Curious Incident of the Dog in the Night-Time | Chapters 157–163 | Summary



Chapter 157

Six days pass before Christopher has the opportunity to sneak back into his father's room to read the rest of the letters. He sits and reads many letters in one sitting. The letters detail Mrs. Boone's life in London with Roger, Mr. Shears. She describes getting a new refrigerator and stove for their apartment, her various jobs, and her reason for leaving him behind. She recounts stressful moments in Christopher's life, like the time he screamed and flailed in the department store during Christmas shopping. He screamed and screamed, refusing to be touched, breaking expensive items on the shelves, and all she could do was wait for the screaming to stop before taking him back home. She describes the decline of communication between herself and Christopher's father as a result of the stress, and the vicious arguments they used to have. She felt like such a terrible mother, she writes, and she thought she was doing what was best for Christopher by leaving him behind.

As Christopher reads, it becomes undeniable there hasn't been a mistake: his mother is alive; his father lied to him. He vomits all over the bed and begins groaning. His father comes home and panics seeing the vomit, the letters, and an unresponsive Christopher. He tries to apologize and explain himself, but Christopher refuses to listen.

Chapter 163

Christopher describes how his brain works in relation to how other people's brains work, again using computers as the metaphor. He claims emotions are just reactions to the pictures around you telling you whether you should laugh or cry, but everyone's mind processes the picture differently.


Finding the letters is a critical turning point for Christopher. He realizes his mother has abandoned him and his father has lied to him—two betrayals so shattering Christopher cannot process them. Unable to express his emotions and feeling lost, Christopher passes out, vomits, and becomes nearly catatonic when his father tries to speak to him. Christopher's entire world view has been created out of the belief in absolute truth. The letters destroy that truth, forcing Christopher to see the world, and himself, differently from now on. They also demonstrate to the reader how much self-control Christopher has shown to this point in the novel and how very sick he is.

For the reader these letters also offer a unique insight into Christopher's character because they are written from the point of view of another character, his mother. Perhaps because she knew Christopher had always strongly valued honesty, she was painfully open with her feelings and with the truth as she saw it. Mrs. Boone shares her darkest emotions, from believing she's a bad mom to worrying whether Christopher would ever live a "normal" life. The stories she shares about Christopher's temper tantrums illustrate the stress the Boone parents live with, but also show how far Christopher has come in managing his condition.

He views social interactions as "puzzles" to be solved, and although he will never process these situations empathically, he has come a long way in understanding how to minimize his stress. The letters also reveal more about his family dynamics. His parents, a heating technician and a secretary, are working class. Most likely they received only basic education, as suggested by Mrs. Boone's many spelling mistakes in the letters. Both Mr. and Mrs. Boone are eager for Christopher to take his important math test and are proud of his intelligence. This highlights a paradox of Christopher's condition: without his disability, his prospects of taking A-level exams and attending university would likely be limited. Although it comes at a great price, Christopher's extraordinary intelligence presents opportunities his parents didn't have.

This section also answers the "whodunit" in Wellington's murder, even as it opens the door to a much more significant new mystery. Mr. Boone's admission likely comes as a shock to readers and Christopher alike. He killed the dog in a fit of rage readers barely glimpsed earlier in his fight with his son. And even this admission undermines Christopher's understanding of the truth: the dog was psychotic and unreliable, not truthful and loyal like Christopher believes. Mr. Boone killed it largely in self-defense because it did not recognize him. For Christopher, all of this reality becomes compounded: the lies his father told him about his mother supplant his father's act of murdering the dog and become one giant act of violence for which Christopher cannot forgive him.

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